Evening star. [volume] (Washington, D.C.) 1854-1972, 1887-03-01
CITY AND DISTRICT.
TREES AND THEIR FOES.
Eo"r insects Charged with Devasta
nng the Shade Trees.


coming summer, and that it may guide the au-
tnor1teS 10 Intelligent action In doing this can
no. so ihto details without making the communi-
oa"oh w long, out In obedience to request from
the commissioners have prepared q more ex-
Cendeo artlcle upon the subject which, with the
accompanying illustrations, will doubtless be &C
season.
There are four insects principally concerned in
Tue oeIOilatlOn OF the shade trees in the CITY of
washington They are: ~ The imported elm-leaf
sHteruca 1q',thomeGna; e. the ragworm
Haf IKE tuSSock moth (Orgyia le,scostig,so) and
w 'n0 i'li "eoworm (Lfyphdntrid cu,sed).
THE ELM LEAF BEETLE.
L. Inc imported elm leaf beetle is small vel
fo"lsn beetle about quarter of an inch long and
marked with two longitudinal dark stripes on the
back. 1t passes the winter in the beetle state in
noes ana crevlces in the bark OF trees in fences
ana Tree boxes, in barns and OuthOuseS etc and
sH Hd ar ald on the young leaves Of elms in
ap d anu May. The eggs are yellOwish, elOngate
ana pointed and laid on end upon the leaves in
giUups, OF from to 20 or more The resulting
and gnawing holes through them. The iarvae mott
IOur tlmeS and transform to pupae at the surface
90 e ee @ under grass and stones There are
pioUuS ana Inc worms are pretty constantly
at WORK through the months OF June, July and
elms genus U1naus,, has prediction for the Eu-
Gpean ein and for trees in Cities and the female
uAcS lOnS INSTANCES.
THE BAG WORM
2. The bag worm is one OF our commonest native
American insects and its bags hang from the
smaller limbs OF our shade trees so as to be easily
seen, especially in winter when the leaves have
Iallen These bags are made by the larva or worm
Wnlcn ilVeS within them. The female moth is wing
passed ner larval and pupal life after she has de-
poslted her eggs In her empty skin or pupar1um
S sd1 tnen ialis 10 the ground and per1sheS The
into nd l>4HnH,
spring into young worms, which scatter and at
once make new bags, which increase with their
me male moth Is a small black hairy-bOdied
creature with ample, transparent Wings and es-
capes from the chrysals after1t is partially worked
OuI vi Inc hmd end OF the bag. This worm is
very general feeder, but is, on the whole more in
furious to evergreens than to trees This
true parasites.
THE TUssOCK-xorH.
.. The white-marked tussock-mOth has a very
Oeautllui hairy larva or caterpillar, marked with
black and yellow and red. The female cocoons are
to be found during the winter on the trees and
nelghDoring fences and tree boxes and each Co
coon Is piaSCered with number OF eggs protected
Dy white frothy glutinOus covering. The eggs
hatch In spring, and the young worms feed upon
et H ISL me males spin their cocoons
moths issue In July, pair and lay eggs for second
brood OF worms which In turn transform and
hibernate. The male moth is active with ample
WINGS which are brown with q CONSPICUOUS white
spot, while the female is pale and wingless, and
only craWlS out OF her cocoon to lay her eggs
thereon and die. This species is never found on
evergreens, and Is chiefly injurious to elms and
ones, because OF the greater shelter which they
Oer for its cocOOns In Washington it Is yet chiefly
confined to our parks, and it has not begun to be
timOre where the trees are older and larger. This
species ALSO has many enemies and nine true par
aS1teS are known to me.
THE WEB WORM.
4. The fall web worm passes the winter in the
pupa state. The cOcOOns are found during the
winter principally at the surface of the ground
mixed with dirt and rubbish or in cracks and
crev1ces Of tree boxes, In fences and under door
steps and basement walls. The first moths issue
hat patches in the underside of the leaves. The
young worms feed preferably In company web
bling hrst one and then several leaves together,
and gradually extending their sphere OF action
until large part of the tree becomes involved.
Ihe worms become full grown in July and spin
cOcOons from which a second generation OF moths
issue early in August and lay eggs, from which
the worms hatch, so that they are once more in
force by the latter part of August. This is the
parent moth is white with varying number OF
spots Is winged in both sexes, and the female
70 S s poSsrs on box elders
WILLOWS. The worm leeds, however, on many
otner trees, but not upon conifers. This species
also mas insect enemies and six true parasites.
SUMMARY OF HABITS.
1t follows from the above that we have to deal
with four very different insects each of them re-
curing modification in treatment especially so
far as winter work is concerned. Here as in every
osner case IN dealing with injurious insects cor
dealt with must necessarily precede intelligent
action, else we shall be apt to err as did the au-
thonies les OF our neighborng city, Baltimore,
necessary expense without producing any benen-
cal result. Their blunder is historical Observing
That the elm trees around Cambridge suffered
from defOnat1On, and were enectually protected by
troughs OF OIL around the trunk they ordered SIM
liar troughs OF Oil to be placed around their trees
In Baltimore, which were also being defoliated In
Cambridge, however, the insect involved was the
spring canker worm (Edledcsitd Uernat0), which
has wingless female that issues from the ground
early In spring, and is enectually prevented by
the oil trough from ascending the trees; whereas
the trees in Baltimore were suffering from the
has ample wings in both sexes
This GG.e,1'ca, or No. !, is therefore injurious
only to elms. It readily flies IN both sexes, pro-
ducss several generations annually and hibernates
In the perfect beetle state
No; 2, the 7nn1dopter.yx, has wingless female
ana consequently restricted powers OF spreading.
IL produces put one generation annually and
hiDernates In the egg state In the bags fOldces
firmly attached to the upper twigs.
and limited po Was OF spfeadina
produces two generations annually and also hiber-
mates In the egg state, but on the outside OF the
tured.
No. 4, the Hyphantria, can fly readily in both
sexes, produces two generations annually, and
hi0ernateS In the third or chrysalis state
WINTER WORK.
The preventive measures that can be taken
during winter time vary according to the species
to be dealt with. For No. 1, the Galeruca which
Is confined to the elmS no treatment OF the trees
themselves or OF the bOxes-in fact, no treatment
that can well be given in the winter SeasOn-will
avail much in destroying the insect In its hiber-
mating retreats, because the parent beetle finds
shelter In all sorts OF -Of-the-way places. 1t
files long distances, especially upon awakening
from its winter tOrpOr that it may ne attracted
to the trees from regions into which it is pract-
cally impossible to enoctualy pursue and detect it,
With No. 2, the ThyrdOpteryx, on the contrary,
effective work can be done during the winter time
or when the trees are bare. The bags which con-
tain the alternating eggs, and which are very
easily detected then, may be gathered or pruned
and burned This work may be SO easily done that
there Is no excuse for the increase OF this species
Where Intelligent action is possible the bags were
better collected and heaped together In some open
enclosure away from trees rather than burned.
Will in time escape, while the young bag
| worms which will In time hatch and which have
feeble travelling power, must needs perish from In
ability to reach proper food.
Much can also be done with No. 8, the Orgy1a,
because tJ also hibernates In the egg state upon
the female cOcOOnS upon the trunks andtn all sorts
of receSSeS.
with regard to No. 4, the Hyphantria, which Is
the species we are more particularly dealing with,
something also may be dOn0in the winter time by
systematic clearing away OF the cOcOOn6 from the